Tibial trial instruments and method of using same

ABSTRACT

An orthopaedic surgical instrument assembly includes a tibial base trial adapted to be positioned on a surgically-prepared proximal end of a patient&#39;s tibia, an intramedullary orthopaedic surgical instrument engaged with a lower surface of the tibial base trial, and a fastener configured to pivot relative to the tibial base trial. The fastener is configured to engage with the intramedullary orthopaedic surgical instrument to removably couple the intramedullary orthopaedic surgical instrument to the tibial base trial.

This application claims priority under 35 U.S.C. §119 to U.S. PatentApplication No. 61/653,363, which was filed on May 30, 2012 and isincorporated herein by reference.

CROSS-REFERENCE

Cross reference is made to copending U.S. patent application Ser. No.______ entitled “TIBIAL ORTHOPAEDIC SURGICAL INSTRUMENTS AND METHOD OFUSING SAME” (Attorney Docket No. 265280-214752, DEP6356USNP1); andcopending U.S. patent application Ser. No. ______ entitled “METHOD OFSURGICALLY PREPARING A PATIENT'S TIBIA” (Attorney Docket No.265280-214775, DEP6356USNP2), each of which is assigned to the sameassignee as the present application, each of which is filed concurrentlyherewith, and each of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to orthopaedic instruments foruse in the performance of an orthopaedic joint replacement procedure,and more particularly to orthopaedic surgical instruments for use in theperformance of a revision knee replacement procedure.

BACKGROUND

Joint arthroplasty is a well-known surgical procedure by which adiseased and/or damaged natural joint is replaced by a prosthetic joint.For example, in a total knee arthroplasty surgical procedure, apatient's natural knee joint is partially or totally replaced by aprosthetic knee joint or knee prosthesis. A typical knee prosthesisincludes a tibial tray, a femoral component, and a polymer insert orbearing positioned between the tibial tray and the femoral component.The tibial tray generally includes a plate having a stem extendingdistally therefrom, and the femoral component generally includes a pairof spaced apart condylar elements, which include surfaces thatarticulate with corresponding surfaces of the polymer bearing. The stemof the tibial tray is configured to be implanted in asurgically-prepared medullary canal of the patient's tibia, and thefemoral component is configured to be coupled to a surgically-prepareddistal end of a patient's femur

From time-to-time, a revision knee surgery may need to be performed on apatient. In such a revision knee surgery, the previously-implanted kneeprosthesis is surgically removed and a replacement knee prosthesis isimplanted. In some revision knee surgeries, all of the components of thepreviously-implanted knee prosthesis, including, for example, the tibialtray, the femoral component, and the polymer bearing, may be surgicallyremoved. In other revision knee surgeries, only part of thepreviously-implanted knee prosthesis may be removed and replaced.

During a revision knee surgery, the orthopaedic surgeon typically uses avariety of different orthopaedic surgical instruments such as, forexample, cutting blocks, surgical reamers, drill guides, prosthetictrials, and other surgical instruments to prepare the patient's bones toreceive the knee prosthesis.

SUMMARY

According to one aspect of the disclosure, an orthopaedic surgicalinstrument assembly is disclosed. The orthopaedic surgical instrumentassembly includes an attachment device, an intramedullary orthopaedicsurgical instrument, and a cutting block. The attachment device includesa housing having a longitudinal axis and a passageway defined thereinthat extends along the longitudinal axis. The attachment device alsoincludes a pair of rails extending outwardly from the housing. Each railhas a longitudinal axis that extends orthogonal to the longitudinal axisof the housing. The attachment device also includes a mounting framepositioned on the pair of rails. The mounting frame is configured toslide relative to the housing along the pair of rails. Theintramedullary orthopaedic surgical instrument includes a shaftpositioned in the passageway of the housing. The cutting block isremovably coupled to the mounting frame.

In some embodiments, the mounting frame may include a biasing elementconfigured to inhibit movement of the mounting frame relative to thehousing. In some embodiments, the biasing element may include a firstcantilevered arm engaged with a first rail of the pair of rails and asecond cantilevered arm engaged with a second rail of the pair of rails.

Additionally, in some embodiments, the cutting block may have a slotdefined therein, and the mounting frame may include a flange that ismoveable between a first position in which a tip of the flange ispositioned in the slot such that the cutting block is secured to themounting frame and a second position in which the tip of the flange isspaced apart from the slot such that the cutting block is removable fromthe mounting frame.

In some embodiments, the mounting frame may include a body having a pairof passageways defined therein and a locking mechanism. Each passagewaymay be sized to receive a rail of the pair of rails. The lockingmechanism may include a flange, a control knob, and a central shaftconnecting the flange to the control knob. The central shaft may bepivotally coupled to the body.

In some embodiments, the cutting block may have a pair of aperturesdefined in an upper surface thereof, and the mounting frame may have apair of alignment pins that are received in the pair of apertures. Insome embodiments, the attachment device may include a locking mechanismattached to the housing. The locking mechanism may be configured tosecure the attachment device to the shaft of the intramedullaryorthopaedic surgical instrument.

Additionally, in some embodiments, the locking mechanism may include alever moveably coupled to the housing. The lever may be moveable betweena first position in which a catch of the lever is engaged with the shaftof the intramedullary orthopaedic surgical instrument and a secondposition in which the catch is disengaged from the shaft.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a surgical reamer and a stem trial. The surgical reamer mayhave a first end attached to the shaft and a second end positionedopposite the first end. The stem trial may be secured to the second endof the surgical reamer.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a broach attached to the shaft. The broach may have atapered outer surface and a plurality of cutting teeth extendingoutwardly from the tapered outer surface. In some embodiments, thebroach may be removably coupled to the shaft. In some embodiments, thecutting block may have a plurality of cutting guides defined therein.

According to another aspect of the disclosure, an orthopaedic surgicalinstrument assembly is disclosed. The orthopaedic surgical instrumentassembly includes a broach, a broach insert, an adaptor, an attachmentdevice, and a cutting block. The broach includes a tapered outersurface, a plurality of cutting teeth formed on the tapered outersurface, and a slot defined in the upper end thereof. The broach insertis configured to be positioned in the slot of the broach. The broachinsert includes a tapered outer surface, and a plurality of cuttingteeth formed on the tapered outer surface. The adaptor includes a baseconfigured to be positioned in the slot of the broach in place of thebroach insert and a shaft extending from the base. The attachment devicehas a passageway defined therein sized to receive the shaft of theadaptor. The cutting block is configured to be coupled to the attachmentdevice.

In some embodiments, the attachment device may include a housing havingthe passageway defined therein and a mounting frame movable relative tothe housing. The mounting frame may be configured to be coupled to thecutting block.

In some embodiments, the cutting block may have a slot defined thereinand a mounting frame. The mounting frame may include a locking tab thatis moveable between a first position in which a tip of the locking tabis positioned in the slot such that the cutting block is secured to themounting frame and a second position in which the tip of the locking tabis spaced apart from the slot such the cutting block is removable fromthe mounting frame.

In some embodiments, the mounting frame may include a locking mechanism.The locking mechanism may include a locking tab, a control knob, and acentral shaft connecting the locking tab to the control knob. The shaftmay have a longitudinal axis extending parallel to the longitudinal axisof the housing of the attachment device. In some embodiments, themounting frame may be removably coupled to the housing.

According to another aspect of the disclosure, an orthopaedic surgicalinstrument assembly is disclosed. The orthopaedic surgical instrumentassembly may include an attachment device, an intramedullary orthopaedicsurgical instrument, and a cutting block. The attachment device includesa housing, a rail extending outwardly from the housing, and a mountingframe positioned on the rail. The mounting frame is configured to sliderelative to the housing along the rail. The intramedullary orthopaedicsurgical instrument is removably coupled to the housing. The cuttingblock is removably coupled to the mounting frame.

In some embodiments, the housing may have a passageway defined thereinand an intramedullary orthopaedic surgical instrument. Theintramedullary orthopaedic surgical instrument may include a shaftpositioned in the passageway of the housing, a stem trial, and asurgical reamer connecting the shaft to the stem trial.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a broach removably coupled to the housing. The broach mayhave a tapered outer surface, and a plurality of cutting teeth formed onthe tapered outer surface.

According to another aspect of the disclosure, an orthopaedic surgicalinstrument assembly is disclosed. The orthopaedic surgical instrumentassembly includes a tibial bearing trial, a tibial base trial, anintramedullary orthopaedic surgical instrument, and a fastener. Thetibial bearing trial includes an articulation surface and a bottomsurface opposite the articulation surface. The tibial base trial isadapted to be positioned on a surgically-prepared proximal end of apatient's tibia. The tibial base trial includes an upper surface engagedwith the bottom surface of the tibial bearing trial. The intramedullaryorthopaedic surgical instrument engages with a lower surface of thetibial base trial. The fastener is configured to pivot relative to thetibial base trial. The fastener includes a button head positioned in anaperture defined in the tibial bearing trial and a threaded shaftengaged with the intramedullary orthopaedic surgical instrument toremovably couple the intramedullary orthopaedic surgical instrument tothe tibial base trial.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a broach engaged with the threaded shaft. The broach mayhave a tapered outer surface and a plurality of cutting teeth formed onthe tapered outer surface.

In some embodiments, a second intramedullary orthopaedic surgicalinstrument may be configured to be engaged with the threaded shaft ofthe fastener in place of the broach. Additionally, in some embodiments,the second intramedullary orthopaedic surgical instrument may include astem trial. In some embodiments, the tibial base trial may include aplate having an opening defined in the upper surface thereof and aplatform positioned in the opening of the plate, and the fastener mayextend through a bore defined in the platform.

In some embodiments, the orthopaedic surgical instrument assembly mayinclude a base insert positioned in the opening defined in the plate ofthe tibial base trial. The base insert may include a lug positioned inthe aperture defined in the tibial bearing trial. In some embodiments,the base insert may further include a frame having a circular openingdefined therein and a pair of prongs extending outwardly from the frame,and the platform of the tibial base trial may be positioned in thecircular opening.

In some embodiments, the base insert may further include a first lowerarm and a second lower arm. The first lower arm may be attached to afirst prong of the pair of prongs. The first lower arm may extendthrough an opening defined in the lower surface of the tibial base trialand may have a tapered outer surface and a plurality of cutting teethformed on the tapered outer surface. The second lower arm may beattached to a second prong of the pair of prongs. The second lower armmay extend through an opening defined in the lower surface of the tibialbase trial and may have a tapered outer surface, and a plurality ofcutting teeth formed on the tapered outer surface.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a slot, and the first lower arm and the second lower arm maybe received in and may extend outwardly from the slot.

In some embodiments, the tibial bearing trial may include a tibialbearing surface trial and a shim. The tibial bearing surface trial mayinclude the articulation surface. The shim may be secured to the tibialbearing surface trial. The shim may include the bottom surface.

According to another aspect, an orthopaedic surgical instrument assemblyis disclosed. The orthopaedic surgical instrument assembly includes atibial base trial, a fastener, an intramedullary orthopaedic surgicalinstrument, and a base insert. The tibial base trial is adapted to bepositioned on a surgically-prepared proximal end of a patient's tibia.The fastener is configured to pivot relative to the tibial base trial.The fastener includes a button head, and a threaded shaft extendingthrough the tibial base trial. The intramedullary orthopaedic surgicalinstrument is secured to the fastener. The base insert is positioned inan opening defined in the tibial base trial.

In some embodiments, an attachment tool may be configured to engage thebase insert to attach and detach the base insert from the tibial basetrial. In some embodiments, the base insert may have a pair of openingsdefined therein, and the attachment tool may include a pair of pegsconfigured to be received in the openings of the base insert. Each pegmay include a spring configured to engage the base insert to secure theattachment tool to the base insert.

In some embodiments, the base insert may include a keel punch. The keelpunch may include a first arm extending through a lower surface of thetibial base trial and a second arm extending through a lower surface ofthe tibial base trial. The first arm may extend through a lower surfaceof the tibial base trial. The first arm may include a tapered outersurface, and a plurality of cutting teeth formed on the tapered outersurface. The second arm may extend through a lower surface of the tibialbase trial. The second arm may include a tapered outer surface, and aplurality of cutting teeth formed on the tapered outer surface.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a slot, and portions of the first arm and the second arm maybe received in and may extend outwardly from the slot.

In some embodiments, the intramedullary orthopaedic surgical instrumentmay include a broach engaged with the threaded shaft. The broach mayinclude a tapered outer surface and a plurality of cutting teeth formedon the tapered outer surface.

In some embodiments, the base insert may include a frame, a pair ofprongs extending outwardly from the frame, and a lug extending upwardlyfrom the frame adjacent to the button head of the fastener.

In some embodiments, a tibial bearing trial may be coupled to the tibialbase trial. The tibial bearing trial may include a tibial bearingsurface trial having an articulation surface, and a shim having anaperture defined therein. The lug of the base insert and the button headof the fastener may be positioned in the aperture.

According to another aspect of the disclosure, an orthopaedic surgicalinstrument assembly is disclosed. The orthopaedic surgical instrumentassembly includes a tibial base trial, a fastener, a first base insert,and a second base insert. The tibial base trial is adapted to bepositioned on a surgically-prepared proximal end of a patient's tibia.The tibial base trial includes a plate having an opening defined in anupper surface thereof, and a platform positioned in the opening of theplate. The fastener is configured to pivot relative to the tibial basetrial. The fastener includes a button head positioned above the uppersurface and a threaded shaft extending through a bore defined in theplatform of the tibial base trial. The first base insert is positionedin the opening defined in the tibial base trial including a framepositioned over the platform of the tibial base trial and a pair ofprongs extending outwardly from the frame. The second base insert isconfigured to be positioned in the opening in place of the first baseinsert. The second base insert includes a first arm extending through alower surface of the tibial base trial and a second arm extendingthrough a lower surface of the tibial base trial. The first arm includesa tapered outer surface and a plurality of cutting teeth formed on thetapered outer surface. The second arm includes a tapered outer surfaceand a plurality of cutting teeth formed on the tapered outer surface.

In some embodiments, a plurality of intramedullary orthopaedic surgicalinstruments may be included. Each intramedullary orthopaedic surgicalinstrument may be configured to engage the fastener to secure theintramedullary orthopaedic surgical instrument to the tibial base trial.

According to another aspect of the disclosure, a method of surgicallypreparing a proximal end of a tibia is disclosed. The method ofsurgically preparing a proximal end of a tibia includes inserting anintramedullary orthopaedic surgical instrument into a medullary canal ofthe tibia, securing a housing of an attachment device to theintramedullary orthopaedic surgical instrument, sliding a mounting framealong a pair of rails toward the housing, attaching a cutting block tothe mounting frame, resecting the proximal end of the tibia using thecutting guide to form a surgically-prepared surface, positioning atibial base trial on the surgically-prepared surface, and inserting akeel punch through a slot defined in the tibial base trial and into thesurgically-prepared surface of the tibia. The cutting block has acutting guide defined therein.

In some embodiments, the method may include attaching a stem trial to anend of a surgical reamer to form the intramedullary orthopaedic surgicalinstrument. This may include inserting the intramedullary orthopaedicsurgical instrument into the medullary canal, which may include reamingthe proximal end of the tibia with the surgical reamer.

In some embodiments, the method may include removing the intramedullaryorthopaedic surgical instrument from the medullary canal, attaching thestem trial to a modular stem, and securing the modular stem and the stemtrial to the tibial base trial. This may include positioning the tibialbase trial on the surgically-prepared surface, which may includeinserting the modular stem and the stem trial into the medullary canal.

In some embodiments, the method may include inserting the keel punchthrough the slot defined in the tibial base trial and into thesurgically-prepared surface of the tibia, which may include inserting aportion of the keel punch into a slot defined in the modular stem.

In some embodiments, the method may include inserting the intramedullaryorthopaedic surgical instrument into the medullary canal of the tibia,which may include inserting a broach into the medullary canal to engagea plurality of cutting teeth with the tibia.

In some embodiments, the method may include withdrawing a broach insertfrom a slot defined in the broach and disengaging the cutting teeth ofthe broach insert from the tibia.

In some embodiments, the method may include attaching a mounting shaftto the broach, which may include securing the housing of the attachmentdevice to the intramedullary orthopaedic surgical instrument, which mayinclude sliding the housing along the mounting shaft.

In some embodiments, the method may include positioning the tibial basetrial on the surgically-prepared surface, which may include engaging afastener with the broach in the medullary canal to secure the tibialbase trial to the broach. In some embodiments, the method may includeinserting the keel punch through the slot defined in the tibial basetrial and into the surgically-prepared surface of the tibia. In someembodiments, inserting the keel punch may include inserting a portion ofthe keel punch into the slot defined in the broach.

In some embodiments, the method may include attaching the cutting blockto the mounting frame, which may include operating a control knob tomove a locking tab of the mounting frame into engagement with thecutting block.

According to another aspect of the disclosure, a method of surgicallypreparing a proximal end of a tibia is disclosed. The method ofsurgically preparing a proximal end of a tibia includes inserting abroach into a medullary canal of the tibia, detaching a broach insertfrom the broach, securing an attachment device to the broach afterdetaching the broach insert, attaching a cutting block to the attachmentdevice, resecting the proximal end of the tibia using the cutting guideto form a surgically-prepared surface, positioning a tibial base trialon the surgically-prepared surface, and securing the tibial base trialto the broach positioned in the medullary canal. The broach includes atapered outer surface and a plurality of cutting teeth formed on thetapered outer surface. The cutting block has a cutting guide definedtherein.

In some embodiments, the method may include inserting a base insert intoan opening defined in the tibial base trial and positioning a tibialbearing trial over the lug of the base insert. The base insert mayinclude a lug.

In some embodiments, the method may include removing the base insertfrom the tibial base trial and inserting a keel punch through a slotdefined in the tibial base trial and into the surgically-preparedsurface of the tibia. In some embodiments, the method may includesecuring the tibial base trial to the broach, which may include rotatinga fastener to threadingly engage the broach.

Additionally, in some embodiments, the method may include securing anadaptor to the broach after detaching the broach insert. This mayinclude securing the attachment device to the broach, which may includesliding the attachment device along a shaft of the adaptor. In someembodiments, the method may include securing the attachment device tothe broach actuating a pair of levers to engage the levers with theshaft of the adaptor. In some embodiments, the method may includesecuring a stem trial to the broach before inserting the broach into themedullary canal.

According to another aspect of the disclosure, a method of surgicallypreparing a proximal end of a tibia is disclosed. The method ofsurgically preparing a proximal end of a tibia includes securing a stemtrial to a surgical reamer, reaming a medullary canal of the tibia withthe surgical reamer, securing an attachment device to a shaft of thesurgical reamer while the surgical reamer and the stem trial arepositioned in the medullary canal, attaching a cutting block to theattachment device, resecting the proximal end of the tibia using thecutting guide to form a surgically-prepared surface, removing thesurgical reamer and the stem trial from the medullary canal, securingthe modular stem and the stem trial to a tibial base trial, insertingthe modular stem and the stem trial into the medullary canal, andpositioning the tibial base trial on the surgically-prepared surface.The cutting block has a cutting guide defined therein.

In some embodiments, the method may include inserting a base insert intoan opening defined in the tibial base trial and positioning a tibialbearing trial over the lug of the base insert. The base insert includesa lug.

In some embodiments, the method may include removing the base insertfrom the tibial base trial and inserting a keel punch through a slotdefined in the tibial base trial and into the surgically-preparedsurface of the tibia.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the following figures,in which:

FIG. 1 is an exploded perspective view of a group of orthopaedicsurgical instruments of an orthopaedic surgical instrument system;

FIG. 2 is a perspective view of an attachment device of the instrumentgroup of FIG. 1;

FIG. 3 is a cross-sectional elevation view of the attachment device ofFIG. 2;

FIG. 4 is a perspective view of a mounting frame of the attachmentdevice of FIG. 2;

FIG. 5 is an elevation view of the mounting frame of FIG. 4;

FIG. 6 is a perspective view of a cutting block of the instrument groupof FIG. 1;

FIG. 7 is an elevation view of a surgical reamer of the instrument groupof FIG. 1;

FIG. 8 is a perspective view of a broach and a broach insert of theinstrument group of FIG. 1;

FIG. 9 is a plan view of the broach of FIG. 8;

FIG. 10 is an elevation view of an adaptor of the instrument group ofFIG. 1;

FIG. 11 is an exploded perspective view of another group of orthopaedicsurgical instruments of the orthopaedic surgical instrument system;

FIG. 12 is a perspective view of a tibial base trial and a fastener ofthe instrument group of FIG. 11;

FIG. 13 is a plan view of the tibial base trial of FIG. 12;

FIG. 14 is a perspective view of one embodiment of a base insert of theinstrument group of FIG. 11;

FIG. 15 is a perspective view of another embodiment of a base insert ofthe instrument group of FIG. 11;

FIG. 16 is an elevation view of an insert attachment tool of theinstrument group of FIG. 11;

FIG. 17 is a plan view of the insert attachment tool of FIG. 16;

FIG. 18 is a perspective view of a number of modular stems of theinstrument group of FIG. 11;

FIG. 19 is a plan view of one of the modular stems of FIG. 18;

FIG. 20 is an exploded perspective view of a tibial base trial, a baseinsert, and a number of tibial bearing trials;

FIGS. 21A and 21B are a simplified flow chart of one embodiment of aprocedure utilizing the orthopaedic surgical instrument system of FIGS.1-20; and

FIGS. 22-33 are views of a patient's tibia and the orthopaedic surgicalinstrument system of FIGS. 1-20 as the orthopaedic surgical instrumentsystem is used in the procedure of FIG. 21.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific exemplary embodimentsthereof have been shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the concepts of the present disclosure tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

Terms representing anatomical references, such as anterior, posterior,medial, lateral, superior, inferior, etcetera, may be used throughoutthe specification in reference to the orthopaedic implants andorthopaedic surgical instruments described herein as well as inreference to the patient's natural anatomy. Such terms havewell-understood meanings in both the study of anatomy and the field oforthopaedics. Use of such anatomical reference terms in the writtendescription and claims is intended to be consistent with theirwell-understood meanings unless noted otherwise.

Referring now to FIG. 1, a group of orthopaedic surgical instruments ofan orthopaedic surgical instrument system 10 (hereinafter instrumentsystem 10) is shown. What is meant herein by the term “orthopaedicsurgical instrument” or “orthopaedic surgical instrument system” is asurgical tool for use by a surgeon in performing an orthopaedic surgicalprocedure. As such, it should be appreciated that, as used herein, theterms “orthopaedic surgical instrument” and “orthopaedic surgicalinstruments” are distinct from orthopaedic implants or prostheses thatare surgically implanted in the body of the patient.

The system 10 includes an attachment device 12, a cutting block 14configured to be secured to the attachment device 12, and a number ofintramedullary orthopaedic surgical instruments 16 configured to beseparately secured to the attachment device 12. What is meant herein bythe term “intramedullary orthopaedic surgical instrument” is a surgicaltool configured to be positioned in the medullary canal of the patient'stibia during the orthopaedic surgical procedure. Examples ofintramedullary orthopaedic surgical instruments include stem trials,broaches, surgical reamers, and the like. As shown in FIG. 1, theintramedullary surgical instruments 16 include a surgical reamer 18, astem trial 20, and a broach assembly 22. As described in greater detailbelow, the surgeon may use attachment device 12 and the intramedullaryorthopaedic surgical instruments 16 position the cutting block 14 foruse during the resection of the proximal end of a patient's tibia.

The attachment device 12 of the system 10 includes an attachment base 30configured to be secured to an intramedullary orthopaedic instrument 16and a mounting frame 32 configured to be moveably coupled to the base30. The mounting frame 32 is also configured to be secured to thecutting block 14, as described in greater detail below. In theillustrative embodiment, the attachment base 30 and the mounting frame32 are formed from a metallic material, such as, for example, stainlesssteel or cobalt chromium. It should be appreciated that in otherembodiments the attachment base 30 or the mounting frame 32 may beformed from a polymeric material.

Referring now to FIGS. 2 and 3, the attachment base 30 includes ahousing 34 and a pair of rails 36, 38 that extend outwardly from thehousing 34. The housing 34 has a longitudinal axis 40 extending from alower end 42 to an upper end 44. The rails 36, 38 extend parallel toeach other, and each rail has an end 46 secured to the housing 34 and atip 48. Each of the rails 36, 38 also has a longitudinal axis 50 thatextends from the end 46 to the tip 48. In the illustrative embodiment,the longitudinal axes 50 of the rails 36, 38 extend orthogonal to thelongitudinal axis 40 of the housing 34. As shown in FIG. 2, each of therails 36, 38 is circular in cross-section, but it should be appreciatedthat in other embodiments each rail may have a square, rectangular, orother cross-sectional shape. It should also be appreciated that in otherembodiments the attachment base 30 may include only a single rail. Inother embodiments, the rails may not extend orthogonal relative to thelongitudinal axis 40 of the housing 34.

The housing 34 of the attachment base 30 has a channel 52 defined in thelower end 42 thereof. The channel 52 is defined by a pair of side walls54 and a substantially planar surface 56 extending between the sidewalls 54. As shown in FIG. 3, the planar surface 56 has an opening 58defined therein, and an inner wall 60 extends upwardly from the opening58 to an opening 62 defined in the upper end 44 of the housing 34. Inthat way, the inner wall 60 defines a passageway 64 through the housing34 that extends along the longitudinal axis 40. As described in greaterdetail below, the passageway 64 is sized to receive a shaft of anintramedullary orthopaedic surgical instrument 16.

The attachment base 30 also includes a locking mechanism 70 configuredto secure the attachment device 12 to the intramedullary orthopaedicsurgical instrument 16. In the illustrative embodiment, the lockingmechanism 70 includes a pair of levers 72 pivotally coupled to thehousing 34. As shown in FIG. 3, each lever 72 includes an arm 74 coupledto the housing 34 via a joint 76. The lever 72 also includes a catch 78extending from one end 80 of the arm 74 and a handle 82 formed on theopposite end 84.

The joint 76 includes a pin 86 that extends through the arm 74 and isreceived in apertures 90 (see FIG. 2) defined in the housing 34. Eachlever 72 is configured to pivot about an axis 92 defined by the pin 86between an engaged position (shown in solid line in FIG. 3) and adisengaged position (shown in broken line in FIG. 3). In the engagedposition, the catch 78 extends through an opening 94 defined in thehousing 34 into the passageway 64. As such, the catch 78 engages aninstrument 16 when the instrument is positioned in the passageway 64. Inthe disengaged position, the catch 78 is removed from the passageway 64such that the catch 78 is disengaged from the instrument 16.

The locking mechanism 70 of the attachment device 12 also includesbiasing elements 100 configured to bias each lever 72 into the engagedposition. In the illustrative embodiment, each biasing element is aspring 100 having an end 102 positioned in an aperture 104 defined inthe end 84 of the arm 74. The opposite end 106 of each spring 100 ispositioned in an aperture 108 defined in the housing 34.

As described above, the attachment device 12 of the system 10 alsoincludes a mounting frame 32 configured to be movably coupled to theattachment base 30. Referring now to FIGS. 4 and 5, the mounting frame32 includes a body 110 having a rear surface 112 that confronts thehousing 34 and a front surface 114 positioned opposite the rear surface112. The front surface 114 has an opening 116 defined therein, and acylindrical inner wall 118 extends inwardly from the opening 116 todefine a passageway 120 extending through the body 110. The passageway120 is sized to receive the rail 36 of the attachment base 30.

The front surface 114 of the body 110 has another opening 122 definedtherein. A cylindrical inner wall 124 extends inwardly from the opening122 to define another passageway 126 through the body 110. As shown inFIG. 4, the passageway 126 extends parallel to the passageway 120, andthe passageway 126 is sized to receive the other rail 38 of theattachment base 30. When the mounting frame 32 is coupled to theattachment base 30, the rails 36, 38 are positioned in the passageways120, 126, and the mounting frame 32 is configured to slide along therails 36, 38 relative to the housing 34 of the attachment base 30.

The mounting frame 32 of the attachment device 12 also includes aretention mechanism 130 configured to inhibit movement of the mountingframe 32 relative to the housing 34. In the illustrative embodiment, theretention mechanism 130 includes a cantilevered arm 132 secured at oneend 134 to the body 110 of the mounting frame 32. As shown in FIG. 4,the cantilevered arm 132 includes a free end 136 configured to engagerail 36 when the mounting frame 32 is coupled to the attachment base 30.The retention mechanism 130 also includes a cantilevered arm 140 thathas a free end 142 configured to engage the other rail 38 when themounting frame 32 is coupled to the attachment base 30. The free ends136, 142 of the arms 132, 140 exert a bias on the rails 36, 38 thatinhibits movement of the mounting frame 32.

In use, when a surgeon or other user applies sufficient force in adirection, for example, toward the attachment base 30, the bias exertedby the cantilevered arms 132, 140 is overcome such that the mountingframe 32 may be advanced along the rails 36, 38 toward the attachmentbase 30. When the surgeon no longer applies the force, the bias exertedby the arms 132, 140 prevents further movement of the mounting frame 32.

In other embodiments, the retention mechanism may include a clampconfigured to be selectively engaged with the rails. In still otherembodiments, the retention mechanism may include a fastener, latch, orother mechanism to prevent relative movement between the mounting frame32 and the attachment base 30. Additionally, in the illustrativeembodiment, the mounting frame 32 is detachable from the attachment base30. It should be appreciated that in other embodiments the attachmentdevice 12 may be configured such the mounting frame 32 is non-removablefrom the attachment base 30.

As described above, the mounting frame 32 of the attachment device 12 isconfigured to be secured to the cutting block 14. As shown in FIGS. 4and 5, the mounting frame 32 includes a locking mechanism 144 configuredto selectively engage the cutting block 14. In the illustrativeembodiment, the locking mechanism 144 includes a central shaft 146pivotally coupled to the body 110 of the mounting frame 32. The centralshaft 146 has a lower end 148 that extends downwardly from the body 110.A plug 150 is formed on the lower end 148 of the central shaft 146, andthe plug 150 includes a pair of flanges 152 that extend outwardly fromthe central shaft 146. As described in greater detail below, the flanges152 are configured to be received in a channel 154 defined in thecutting block 14 to selectively secure the cutting block 14 to themounting frame 32.

As shown in FIG. 4, the central shaft 146 of the locking mechanism 144has a longitudinal axis 156. The locking mechanism 144 also includes acontrol knob 158 operable to rotate the central shaft 146 (and henceplug 150) about the axis 156. In the illustrative embodiment, thecontrol knob 158 includes an arm 160 secured to the central shaft 146.The arm 160 extends outwardly from the central shaft 146 through a slot162 defined in the front surface 114 of the body 110. The arm 160includes a grip 164 that is spaced apart from the body 110, and the grip164 may be grasped by the user to operate the control knob 158.

The control knob 158 is operable to rotate the plug 150 in the directionindicated by arrow 166 between an engaged position (see FIG. 4) and adisengaged position (see FIG. 5). In the engaged position, the flanges152 are received in the channel 154 defined in the cutting block 14,thereby securing the cutting block 14 to the mounting frame 32. In thedisengaged position, the flanges 152 are removed from the channel 154,thereby releasing the block 14. As shown in FIG. 5, the arm 160 of thecontrol knob 158 is positioned between a pair of lips 168 formed on thebody 110 when the plug 150 is in the disengaged position.

In other embodiments, the control knob may have a handle or grip securedto the upper end of the central shaft 146. In still other embodiments,the locking mechanism 144 may include a lever pivotally coupled themounting frame that is selectively engaged with and disengaged with thecutting block. In other embodiments, the locking mechanism 144 mayinclude any combination of latches or other fasteners to secure thecutting block 14 to the attachment device 12.

As shown in FIGS. 4 and 5, the mounting frame 32 also includes a pair ofalignment pins 170 extending downwardly from the body 110. Eachalignment pin 170 is sized and shaped to be received in an aperture 172defined in the cutting block 14. In the illustrative embodiment, eachpin 170 has a circular cross section. It should be appreciated that inother embodiments each pin may have a square, rectangular, or othercross-sectional shape.

Referring now to FIG. 6, the system 10 includes a cutting block 14. Thecutting block 14 includes a posterior side wall 200 that is configuredto confront the anterior side of the patient's tibia, as described ingreater detail below. The cutting block 14 also includes an anteriorside wall 202 that is positioned opposite the posterior side wall 200.An upper surface 204 connects the side walls 200, 202. In theillustrative embodiment, the cutting block 14 is formed from a metallicmaterial, such as, for example, stainless steel or cobalt chromium.

An opening 206 is defined in the upper surface 204, and an inner wall208 extends downwardly from the opening 206 to define a slot 210 in thecutting block 14. As shown in FIG. 6, the slot 210 has an open end 212defined in the anterior side wall 202, and a closed end 214 positionedbetween the side walls 200, 202. The inner wall 208 has a channel 154defined therein. As described above, the channel 154 is sized to receivethe flanges 152 of the locking mechanism 144 to secure the cutting block14 to the attachment device 12.

The cutting block 14 also includes a pair of apertures 172 positioned oneach side of the slot 210. As described above, the apertures 172 aresized to receive the alignment pins 170 of the mounting frame 32.

The cutting block 14 includes a number of cutting guides 220 that may beused during an orthopaedic surgical procedure to resect a portion of thepatient's bone. Each cutting guide 220 includes an elongated slot sizedto receive a cutting saw blade of a surgical saw or other surgicaldevice. In the illustrative embodiment, the cutting block 14 has fourcutting guides 220 extending through the side walls 200, 202. Eachcutting guide 220 includes a planar surface 222 that defines a resectionplane 224.

The resection planes 224 extend through the patient's tibia when thecutting block 14 is secured to the attachment device 12 on the tibia. Inthat way, the cutting guides 220 may be used by the orthopaedic surgeonduring the resection of the patient's tibia. In the illustrativeembodiment, the cutting guides 220 (hence the resection planes 224) arespaced part from each other by about five millimeters. As such, thesurgeon may select the particular cutting guide 220 corresponding to theamount of bone to be removed. In other embodiments, the cutting block 14may include any number of cutting guides 220, which may be spaced apartby an amount greater than or less than five millimeters.

As shown in FIG. 6, the cutting block 14 includes a plurality offastener guides 226. Each guide 226 includes a bore 228 sized to receivefasteners such as, for example, fixation pins 230 (see FIG. 24), whichmay be utilized to secure the cutting block 14 to the patient's tibia.It should be appreciated that in other embodiments the cutting block 14may include additional fastener guides 226 or other fastening elementsto secure the cutting block to the patient's tibia. The angle of eachfastener guide 226 may also vary to provide additional security with thebone.

As described above, the system 10 also includes a number ofintramedullary orthopaedic surgical instruments 16, including a surgicalreamer 18 (see FIG. 7), a stem trial 20 (see FIG. 1), and a broachassembly 22 (see FIGS. 8-10). In the illustrative embodiment, each ofthe intramedullary orthopaedic surgical instruments 16 is formed from ametallic material, such as, for example, stainless steel or cobaltchromium. Referring now to FIG. 7, the surgical reamer 18 includes acutting head 240 and an elongated shaft or shank 242 secured to thecutting head 240. In the illustrative embodiment, the cutting head 240is conical and extends from a tip 244 to an upper end 246. The tip 244of the cutting head 240 has an aperture 248 defined therein. An innerwall 250 defines the aperture 248, and the inner wall 250 has aplurality of internal threads (not shown) formed thereon.

The cutting head 240 of the reamer 18 includes a plurality of cuttingflutes 252 extending between the tip 244 and the end 246. When thesurgical reamer 18 is positioned in the medullary canal 254 (see FIG.23) of the patient's tibia and rotated, the cutting flutes 252 of thecutting head 240 ream or otherwise cut the bone tissue of the tibia. Itshould be appreciated that other reamers having cutting heads ofdifferent configurations may be provided. For example, the outerdiameter of the cutting head may vary to produce reamed canals sized toaccommodate prosthetic components of different sizes. Additionally, thelength of the cutting head may vary to change the depth of the reamedcanal.

The shank 242 of the surgical reamer 18 has a platform 256 attached tothe cutting head 240 and an upper end 258 that fits into the chuck of arotary power tool or a manual handle. A cylindrical body 260 ispositioned between the upper end 258 and the platform 256. Thecylindrical body 260 is sized to be positioned in the passageway 64defined in the attachment base 30. A recess 262 is defined in thecylindrical body 260 and is sized to receive the catches 78 of thelevers 72 of the attachment base 30.

When the attachment device 12 is secured to the surgical reamer 18, thelower end 42 of the attachment base 30 is seated on the platform 256 ofthe shank 242. As shown in FIG. 7, the cylindrical body 260 of the shank242 has a lower end 264 that extends upwardly from the platform 256. Thelower end 264 of the body 260 is received in the channel 52 defined inthe attachment base 30 when the attachment device 12 is seated on theshank 242. The catches 78 of the levers 72 are positioned in the recess262 of the cylindrical body 26. In the illustrative embodiment, thecylindrical body 260 has a stop surface 266 that is configured to engagethe catches 78 to prevent the attachment device 12 from being removedfrom the reamer 18.

Returning to FIG. 1, the system 10 also includes a stem trial 20. Itshould be appreciated that other stem trials having differentconfigurations may be provided. For example, the outer diameter and/orlength of the stem trial may vary to trial prosthetic components ofdifferent sizes. In the illustrative embodiment, the stem trial 20 has abody 268 that extends from a tip 270 to an upper end 272. The upper end272 has a plurality of external threads 274 that correspond to theinternal threads surrounding the aperture 248 of the shank 242. Theupper end 272 of the stem trial 20 is sized to be received in theaperture 248 to engage the internal threads with the external threads274 and thereby secure the stem trial 20 to the surgical reamer 18. Itshould be appreciated that in other embodiments the stem trial 20 may beengaged with surgical reamer 18 without being secured thereto.

As described above, the intramedullary orthopaedic surgical instruments16 of the system 10 include a broach assembly 22 configured to bepositioned in the medullary canal 254 of the patient's tibia. Referringnow to FIGS. 8 and 9, the broach assembly 22 includes a broach 280 and abroach insert 282 configured to be removably coupled to the broach 280.The broach 280 includes an outer surface 284 extending from a tip 286 toan upper end 288. The outer surface 284 is tapered, with the diameter ofthe broach 280 decreasing from the upper end 288 to the tip 286.

A plurality of cutting teeth 290 are formed on the outer surface 284between the tip 286 and the upper end 288. As described in greaterdetail below, the cutting teeth 290 are configured to engage the bonesurrounding the medullary canal 254 when the broach 280 is insertedtherein. It should be appreciated that other broaches having differentconfigurations may be provided. For example, the outer diameter and/orlength of the broach may vary to produce different sized canals toaccommodate prosthetic components of different sizes.

As shown in FIG. 8, the tip 286 of the broach 280 has an aperture 302defined therein. An inner wall 304 defines the aperture 302, and theinner wall 304 has a plurality of internal threads (not shown) formedthereon. The aperture 302 is sized to receive the upper end 272 of thestem trial 20 such that the internal threads engage with the externalthreads 274 and thereby secure the stem trial 20 to the broach 280.

The broach 280 includes a substantially planar top surface 306 at theupper end 288 thereof. An opening 308 is defined in the top surface 306,and the broach 280 has inner walls 310, 312 that extend downwardly fromthe top surface 306. The inner walls 310, 312 cooperate with a bottomwall 314 to define a slot 316 in the broach 280. As shown in FIGS. 8 and9, the slot 316 extends through the outer surface 284 of the broach 280.

The inner wall 310 of the broach 280 has a planar surface 318 thatextends inwardly from the outer surface 284. The other inner wall 312has a pair of planar surfaces 320, 322 that extend inwardly from theouter surface 284. As shown in FIG. 9, the planar surface 322 extends atan oblique angle α relative to the planar surface 320. An arcuatesurface 324 connects the planar surface 322 to the planar surface 320.

A platform 328 extending upwardly from the bottom wall 314 is positionedin the slot 316. The platform 328 has a top surface 330 and an opening332 defined in the top surface 330. A cylindrical wall 334 extendsinwardly from the opening 332 to a lower surface 336. The lower surface336 and the cylindrical wall 334 cooperate to define a bore 338 in theplatform 328. As shown in FIG. 9, the lower surface 336 has anotheropening 340 defined therein, and another cylindrical wall 342 extendsinwardly from the opening 340. The cylindrical wall 342 defines anaperture 344 within the broach 280 and has a plurality of internalthreads 346 formed thereon.

The upper end 288 of the broach 280 has another slot 350 definedtherein. The slot 350 extends inwardly from the outer surface 284through the top surface 306 to a side wall 352. A flange 354 extendsfrom the side wall 352 into the slot 350. Another slot 356 is formed inthe upper end 288. As shown in FIG. 9, the slot 356 opens into the slot316.

As described above, the broach assembly 22 also includes a broach insert282. As shown in FIG. 8, the broach insert 282 is sized and shaped to bereceived in the slot 316 defined in the broach 280. The broach insert282 has a pair of side walls 362, 364 that confront the inner walls 310,312, respectively, of the broach 280 when the broach insert 282 ispositioned in the slot 316. The side wall 362 of the broach insert 282has a planar surface 366 that engages the planar surface 318 of thebroach 280 when the broach insert 282 is coupled to the broach 280. Theother side wall 362 has a pair of planar surfaces 368, 370 thatcorrespond to and engage the planar surfaces 320, 322 of the broach 280when the broach insert 282 is coupled to the broach 280.

The broach insert 282 includes a main body 372 that has an upper surface374. As shown in FIG. 8, the upper surface 374 has a central slot 376defined therein. Another slot 378 is defined in the upper surface 374adjacent to the central slot 376. A flange 380 extends into the slot378.

The broach insert 282 includes a pair of legs 382 that extend downwardlyfrom the main body 372. An opening 384 is defined between the legs 382.As shown in FIG. 8, the opening 384 is sized to receive the platform 328of the broach 280. When the broach insert 282 is receive in the slot 316of the broach 280, the legs 382 engage the bottom wall 314 and arepositioned on each side of the platform 328.

The broach insert 282, like the broach 280, has an outer surface 386that is tapered. The outer surface 386 has a plurality of cutting teeth388 formed on the outer surface 284. As described in greater detailbelow, the cutting teeth 388 are configured to engage the bonesurrounding the medullary canal 254 when the broach insert 282 isinserted therein.

Returning to FIG. 1, the broach assembly 22 also includes an adaptor 400configured to connect the broach 280 to the attachment device 12. Theadaptor 400 includes a base 402 and a plug 404 secured to the base 402.The adaptor 400 is configured to be coupled to the broach 280, and theplug 404 is configured to be positioned in the slot 316 when the adaptor400 is coupled to the broach 280. The plug 404 includes a pair of sidewalls 406, 408 that confront the inner walls 310, 312, respectively, ofthe broach 280 when the plug 404 is positioned in the slot 316. The sidewall 406 of the plug 404 has a planar surface 410 that engages theplanar surface 318 of the broach 280 when the adaptor 400 is coupled tothe broach 280. The other side wall 408 has a pair of planar surfaces412, 414 that correspond to and engage the planar surfaces 320, 322 ofthe broach 280 when the adaptor 400 is coupled to the broach 280.

As shown in FIG. 10, the adaptor 400 includes a post 416 extendingdownwardly from the plug 404. The post 416 is configured to be receivedin the bore 338 defined in the platform 328 of the broach 280 when theadaptor 400 is secured to the broach 280. The adaptor 400 includes abiasing element 418 configured to retain the adaptor 400 on the broach280. In the illustrative embodiment, the biasing element 418 is acantilevered spring 420 configured to engage the inner wall 310 of thebroach 280 when the adaptor 400 is positioned in the slot 316. It shouldbe appreciated that in other embodiments the adaptor 400 may includelatches, pins, or other fasteners to secure to the adaptor 400 to thebroach 280.

Another shaft 422 extends upwardly from the base 402. The shaft 422 issized to be positioned in the passageway 64 defined in the attachmentbase 30. A recess 424 is defined in the shaft 422 and is sized toreceive the catches 78 of the levers 72 of the attachment device 12.When the attachment device 12 is secured to the adaptor 400, the lowerend 42 of the attachment base 30 is seated on the plug 404 of theadaptor 400. The base 402 of the adaptor 400 is received in the channel52 defined in the attachment base 30 when the attachment device 12 isseated on the adaptor 400. The catches 78 of the levers 72 arepositioned in the recess 424 of the shaft 422. In the illustrativeembodiment, the shaft 422 has a stop surface 426 that is configured toengage the catches 78 to prevent the attachment device 12 from beingremoved from the adaptor 400.

Referring now to FIGS. 11-20, the orthopaedic surgical instrument system10 includes a tibial tray trial assembly 432 (see FIG. 11) and a numberof tibial bearing trial assemblies 434 (see FIG. 20) that may be used tosize and select the prosthetic components of a knee prosthesis that willreplace the patient's natural joint. As shown in FIG. 11, the tibialtray trial assembly 432 includes a tibial base trial 436, a number ofbase inserts 438, and a number of intramedullary surgical instruments440. In the illustrative embodiment, the tibial tray trial assembly 432is formed from a metallic material, such as, for example, stainlesssteel or cobalt chromium.

Referring now to FIG. 12, the base trial 436 includes a plate 442 havingan upper surface 444, a lower surface 446, and an outer side wall 448extending between the surfaces 444, 446. The plate 442 has a plateopening 450 defined in the upper surface 452. The plate opening 450 hasa central opening 454 and a pair of elongated openings 456 extendingoutwardly therefrom. An inner wall 458 extends downwardly from theopening 450 to define a passageway 460 and a passageway 462 through theplate 442. As will be described in greater detail below, theconfiguration of the passageways 460, 462 permits the advancement of akeel punch and various other instruments into the proximal end of thepatient's tibia. It should be appreciated that the tibial base trial 436may be formed in a number of different sizes to accommodate tibias ofvarious sizes.

The inner wall 458 includes an upper wall 464 and a lower wall 466offset or otherwise spaced inwardly from the upper wall 464. The upperwall 464 and the lower wall 466 cooperate to define a shelf surface 468therebetween. A platform 470 is positioned in the central opening 454 ofthe plate 442. As shown in FIG. 12, the platform 470 extends upwardlyfrom the shelf surface 468 and has a top surface 472 that is co-planarwith the upper surface 444 of the plate 442.

In the illustrative embodiment, the plate 442 also includes alever-receiving notch 480 that is defined in an anterior aspect 482thereof. The notch 480 includes a channel 484 that is defined in theupper surface 444 and extends posteriorly from the outer side wall 448.An oblong-shaped slot 490 is defined in the posterior end 492 of thechannel 484. The slot 494 extends downwardly through the lower surface446 of the plate 442. As shown in FIG. 12, a pair of oblong-shapedapertures 496 are defined in the side wall 448, one on each side of thenotch 480. The notch 480 and the apertures 496 are configured to receivea lever and a pair of pins, respectively, associated with an alignmenthandle.

As shown in FIG. 13, a pin 486 extends downwardly from the lower surface446 of the plate 442. As described in greater detail below, the pin 486is sized to be received in the slot 356 defined in the broach 280. Theplate 442 also includes a number of fastener guides 498 that are definedin the anterior aspect 482 thereof. Each fastener guide 498 includes abore 500 configured to receive a fastener such as a fixation pin, whichmay be utilized to secure the base trial 436 to the proximal end of thepatient's tibia.

As shown in FIG. 12, the tibial base trial assembly 432 includes alocking mechanism 510 configured to secure the tibial base trial 436 toone of the intramedullary orthopaedic surgical instruments 440. In theillustrative embodiment, the locking mechanism 510 includes a fastener512 pivotally coupled to the tibial base trial 436. The fastener 512 ispermanently secured to the plate 442 of the tibial base trial 436, butit should be appreciated that in other embodiments the fastener may beremovable from the tibial base trial or secured to the intramedullaryorthopaedic surgical instruments.

The fastener 512 of the locking mechanism 510 includes a button head 514positioned above the top surface 472 of the platform 470 and a centralshaft 516 secured to the button head 514. The central shaft 516 extendsthrough an opening (not shown) defined in the platform 470 to a lowerend 518. An outer sleeve 520 is secured to the central shaft 516 betweenthe lower end 518 and the lower surface 446 of the plate 442, therebysecuring the fastener 512 to the base trial 436. As shown in FIG. 12,the fastener 512 includes a plurality of external threads 522 that areformed on the lower end 518 of the central shaft 516. The externalthreads 522 of the fastener 512 engage internal threads formed on anintramedullary surgical instrument 440 to secure the intramedullarysurgical instrument 440 to the base trial 436.

For example, as shown FIG. 11, the intramedullary surgical instruments440 include the broach 280, which is configured to be coupled to thebase trial 436 via the fastener 512. As described above, the broach 280has a bore 338 defined therein and an aperture 344 positioned below thebore 338. The aperture 344 is defined by a cylindrical wall 342 that hasa plurality of internal threads 346 formed thereon. To secure the broach280 to the base trial 436, the base trial 436 is aligned with the broach280 and the lower end 518 of the fastener 512 is advanced into the bore338. The external threads 522 formed on the fastener 512 are advancedinto contact with the internal threads 346 of the broach 280. Byrotating the fastener 512 about the longitudinal axis 530, the internalthreads 346 are engaged with external threads 522, thereby securing thebroach 280 to the base trial 436. When the base trial 436 is seated onthe top surface 306 of the broach 280, the outer sleeve 520 of thefastener 512 is positioned in the bore 338 of the broach 280.

When the broach 280 is secured to the base trial 436, the base trial 436is permitted to rotate relative to the broach 280. As described above,the pin 486 is received in the slot 356 when the broach 280 is securedto the base trial 436. The slot 356 is sized such that the pin 486 maymove within the slot 356, thereby permitting the base trial 436 torotate relative to the broach 280 during the orthopaedic surgicalprocedure.

The button head 514 of the fastener 512 includes a neck 524 thatconfronts the platform 470 of the base trial 436 and a knob 526 securedto the neck 524. The knob 526 has a knurled outer surface 528 that maybe grasped by the surgeon to rotate the fastener 512 about thelongitudinal axis 530. The button head 514 also has a socket 532 definedtherein, which is sized to receive a driver or other surgical tool torotate the fastener 512 about the axis 530.

Referring now to FIGS. 14 and 15, the system 10 further includes a pairof base inserts 438. The base inserts 438 are configured to bepositioned separately in the plate opening 450 of the base trial 436.Each base insert 438 has a lower surface 540 configured to engage theshelf surface 468 of the base trial 436 when the base insert 438 isseated on the base trial 436 and an upper surface 542 positionedopposite the lower surface 540. The base insert 438 includes a centralframe 546 sized to be received in the central opening 454 of the basetrial 436. The central frame 546 has a cylindrical slot 548 definedtherein, which is sized to receive the platform 470 of the base trial436. A lug 544 extends upwardly from the upper surface 542 adjacent tothe slot 548.

The base insert 438 also includes a pair of prongs 550, 552 that extendoutwardly from the central frame 546 to ends 554, 556, respectively. Theprongs 550, 552 are sized to be received in the elongated openings 456of the base trial 436. The prong 550 has a bore 558 defined therein atthe end 554 thereof. Similarly, the prong 552 has a bore 560 definedtherein at the end 556 thereof. The bores 558, 560 are sized to receivepegs 562, 564 of the attachment tool 566, as described in greater detailbelow.

The base inserts 438 include a check insert 570 (see FIG. 14) and a keelpunch insert 572 (see FIG. 15). The keel punch insert 572 includes apair of lower arms 574, 476 that extend downwardly from the prongs 550,552, respectively. Each of the lower arm 574, 576 includes a taperedouter surface 578 that has a plurality of cutting teeth 580 formedthereon.

Returning to FIG. 11, the system 10 includes the attachment tool 566,which may be used by the surgeon to attach and detach the base inserts438 from the base trial 436. In the illustrative embodiment, theattachment tool 566 includes a main body 590 and a pair of arms 592, 594extending outwardly from the main body 590. The main body 590corresponds to the central frame 546 of the base insert 438, and thearms 592, 594 correspond to the prongs 550, 552, respectively, of thebase insert 438. The attachment tool 566 has a lower surface 596 thatengages the upper surface 542 of the base insert 438 when the baseinsert 438 is secured thereto.

As shown in FIGS. 16 and 17, the arm 592 of the tool 566 has a peg 598extending downwardly from the lower surface 596. The peg 598 iscylindrical and is sized to be received in the bore 558 defined in theend 554 of the prong 550. The peg 598 has an annular slot 600 definedtherein, and a biasing element 602 is positioned in the slot 600. Thebiasing element 602 is configured to engage the prong 550 when the peg598 is positioned in the bore 558 to secure the base insert 438 to theattachment tool 566. In the illustrative embodiment, the biasing element602 is a ring-shaped coil. It should be appreciated that in otherembodiments the spring may take the form of another biasing or frictionelement, such as, for example, an o-ring or a retaining ring.

The other arm 594 of the tool 566 also has a peg 604 extendingdownwardly from the lower surface 596. The peg 604 is cylindrical and issized to be received in the bore 560 defined in the end 556 of the prong552. The peg 604 has an annular slot 606 defined therein, and a biasingelement 602 is positioned in the slot 600. The biasing element 602 isconfigured to engage the prong 552 when the peg 604 is positioned in thebore 560 to secure the base insert 438 to the attachment tool 566.

The attachment tool 566 has an upper surface 610 positioned opposite thelower surface 596. The main body 590 has a slot 612 that extends throughthe upper surface 610 and inwardly from the outer surface 614. As shownin FIG. 16, the main body 590 also includes a flange 616 that extendsinto the slot 612. The main body 590 also includes a central bore 618that is defined in the upper surface 610.

As shown in FIG. 17, the lower surface 596 of the attachment tool 566has an opening 620 defined therein. An inner wall 622 extends inwardlyfrom the opening 620 to define an aperture 624 in the main body 590 ofthe tool 566. The aperture 624 is sized to receive the button head 514of the fastener 512 when the tool 566 is secured to the base insert 438on the base trial 436.

Returning to FIG. 11, the system 10 includes a number of intramedullaryorthopaedic surgical instruments 440 that are configured to be coupledto the base trial 436. The instruments 440 include the broach 280, thestem trial 20, and a modular stem 630. It should be appreciated thatother modular stems having different configurations may be provided. Forexample, as shown in FIG. 18, the outer diameter and/or length of themodular stem may vary to produce different sized canals to accommodateprosthetic components of different sizes.

The modular stem 630 includes an outer surface 632 extending from a tip634 to an upper end 636. The outer surface 632 is tapered, with thediameter of the modular stem 630 decreasing from the upper end 636 tothe tip 634. As shown in FIG. 18, the tip 634 of the modular stem 630has an aperture 638 defined therein. An inner wall 640 defines theaperture 638, and the inner wall 640 has a plurality of internal threads(not shown) formed thereon. As described above, the stem trial 20includes a plurality of external threads 274, and the aperture 638 issized to receive the upper end 272 of the stem trial 20 such that theinternal threads engage with the external threads 274 to thereby securethe stem trial 20 to the modular stem 630.

The modular stem 630 includes a substantially planar top surface 642 atthe upper end 636 thereof. An opening 644 is defined in the top surface642, and the modular stem 630 has inner walls 646, 648 that extenddownwardly from the top surface 642. The inner walls 646, 648 cooperatewith a bottom wall 650 to define a slot 652 in the modular stem 630. Asshown in FIGS. 18 and 19, the slot 652 extends through the outer surface632 of the modular stem 630.

A platform 654 extending upwardly from the bottom wall 650 is positionedin the slot 652. The platform 654 has a top surface 656 and an opening658 defined in the top surface 656. A cylindrical wall 660 extendsinwardly from the opening 658 to a lower surface 664. The lower surface664 and the cylindrical wall 660 cooperate to define a bore 668 in theplatform 654. As shown in FIG. 19, the lower surface 664 has anotheropening 670 defined therein, and another cylindrical wall 672 extendsinwardly from the opening 670. The cylindrical wall 672 defines anaperture 674 within the modular stem 630 and has a plurality of internalthreads 676 formed thereon.

To secure the modular stem 630 to the base trial 436, the base trial 436is aligned with the modular stem 630 and the lower end 518 of thefastener 512 is advanced into the bore 668. The external threads 522formed on the fastener 512 are advanced into contact with the internalthreads 676 of the modular stem 630. By rotating the fastener 512 aboutthe longitudinal axis 530, the internal threads 676 are engaged withexternal threads 522, thereby securing the modular stem 630 to the basetrial 436. When the base trial 436 is seated on the top surface 656 ofthe modular stem 630, the outer sleeve 520 of the fastener 512 ispositioned in the bore 668 of the modular stem 630.

As described above, the system 10 also includes a number of tibialbearing trial assemblies 434. An tibial bearing trial assembly 434 isdisclosed in U.S. Patent App. Ser. No. 61/503,300, filed Jun. 30, 2011and entitled “TRIALING SYSTEM FOR A KNEE PROSTHESIS AND METHOD OF USE,”by Thomas E. Wogoman et al. (Attorney Docket No. 265280-210420,DEP6286USPSP), which is incorporated herein by reference. It should beappreciated that in other embodiments the tibial bearing trial may be amonolithic component, and the system 10 may include multiple tibialbearing trials different sizes and configurations.

Referring now to FIG. 20, each tibial bearing trial assembly 434 is amulti-piece assembly configured to assist the surgeon in selecting asize and configuration of a prosthetic tibial bearing component of theknee prosthesis. A tibial bearing trial 434 may be assembled with one ofa number of tibial bearing surface trials 680 and one of a number of aplurality of trial shims 682. Each bearing surface trial 680 has adifferent size and/or configuration, and each shim 682 has a differentthickness. Because each shim 682 is configured to be secured to eachbearing surface trial 680, the surgeon is able to assemble a tibialbearing trial 434 of one size and configuration, evaluate theperformance of that tibial bearing trial 434, and then modify the tibialbearing trial 434 as necessary to determine intraoperatively the typeand configuration of the prosthetic tibial bearing component to beimplanted.

As shown in FIG. 20, one of the bearing surface trials 680 is a fixedbearing surface trial 684. The term “fixed bearing surface trial” asused herein refers to a bearing surface trial that is fixed in positionrelative to the tibial base trial 436 when the bearing surface trial andshim are attached thereto (i.e., it is configured to not substantiallyrotate or move in the anterior-posterior direction or medial-lateraldirection relative to the tibial base trial 436). The fixed bearingsurface trial 684 may be embodied as a cruciate retaining trial, aposterior stabilized trial, a revision trial, or other surface trialconfiguration, per the surgeon's preference. For example, in embodimentswhere the fixed bearing surface trial 684 is embodied as a posteriorstabilized trial, the fixed bearing surface trial 684 may include aspine extending upwardly from the upper bearing surface of the trial684.

The fixed bearing surface trial 684 has a platform 686 including a lowersurface 688 that contacts the shim 682 when the shim 682 is securedthereto. The platform 686 also includes a pair of articulation surfaces690 that are positioned opposite the lower surface 688. The articulationsurfaces 690 are configured to rotate with the condyle surfaces of afemoral surgical instrument of a femoral prosthetic component.

The other bearing surface trial 680 is embodied as a mobile bearingsurface trial 700. The term “mobile bearing surface trial” as usedherein refers to a bearing surface trial that is permitted to rotaterelative to the tibial base trial 436 when the bearing surface trial andthe shim are attached thereto (i.e., it is configured to substantiallyrotate or move in the anterior-posterior direction or the medial-lateraldirection relative to the tibial base trial 436). The mobile bearingsurface trial 700 may be embodied as a cruciate retaining trial, aposterior stabilized trial, a revision trial, or other surface trialconfiguration, per the surgeon's preference. For example, in embodimentswhere the mobile bearing surface trial 700 is embodied as a posteriorstabilized trial, the mobile bearing surface trial 700 may include aspine extending upwardly from the upper bearing surface thereof.

The mobile bearing surface trial 700 has a platform 702 including alower surface 704 the shim 682 when the shim 682 is secured thereto. Theplatform 702 also includes a pair of articulation surfaces 706 that arepositioned opposite the lower surface 704. The articulation surfaces 706are configured to rotate with the condyle surfaces of a femoral surgicalinstrument or femoral prosthetic component.

As described above, the surface trials 684, 700 are configured to besecured with a trial shim 682. The shim 682 has an aperture 708 definedtherein, which is configured to receive the button head 514 of thefastener 512 secured to the base trial 436 and the lug 544 of the baseinsert 438 when the shim 682 is positioned on the base trial 436. Eachshim 682 also includes a pair of through-holes 710, which are configuredto receive fastener pegs (not shown) of the tibial bearing surfacetrials 680 to secure the shim 682 to each trial 680.

The aperture 708 also includes a central passageway 712, a rectangularslot 714 extending outwardly from the central passageway 712, and anarcuate slot 716. The central passageway 712 is sized to receive thebutton head 514. As will be described in greater detail below, therectangular slot 714 is sized to receive the lug 544 when the shim 682is attached to a fixed bearing surface trial 684 on the base trial 436.The arcuate slot 716 is also sized to receive the lug 544 when the shim682 is attached to a mobile bearing surface trial 700, therebypermitting the mobile bearing surface trial 700 to rotate relative tothe base trial 436.

The system 10 may be utilized during the performance of an orthopaedicsurgical procedure similar to that shown in FIGS. 21A and 21B. As shownin FIGS. 22-24 and 30-32, the surgeon may initially prepare themedullary canal and determine whether the patient requires a tibialsleeve. The surgeon may then insert an intramedullary orthopaedicsurgical instrument 16, such as, for example, the surgical reamer 18 orthe broach assembly 22 into the medullary canal. The surgeon may securethe attachment device 12 and the cutting block 14 to the intramedullaryorthopaedic surgical instrument 16 and perform a resection of thepatient's tibia.

As shown in FIGS. 25-29, the surgeon may assemble a tibial tray trial432 and perform a trial reduction with a tibial bearing trial 434. Thesurgeon may then impact a keel punch insert 572 into the patient's tibiabefore removing the tibial tray trial 432 therefrom.

Referring now to FIGS. 21A and 21B, an illustrative orthopaedic surgicalprocedure 800 utilizing the system 10 is shown. In procedure block 802,a medullary canal 254 of a patient's tibia 720 is initially prepared. Todo so, an orthopaedic surgeon may insert an initial surgical reamer 722into the medullary canal 254. As shown in FIG. 22, the surgeon may usethe reamer 722 to drill and/or ream the medullary canal 254 to the depthand/or diameter required receive the intramedullary orthopaedic surgicalinstrument 16. Multiple drills or reamers may be used to increase thesize of the opening 724 of the medullary canal 254 formed on theproximal end 726 of the patient's tibia 720.

In procedure block 804 of the surgical procedure 800, the surgeondetermines whether a prosthetic sleeve will be included with the tibialprosthetic component. The surgeon may make this determinationpre-operatively or intraoperatively, depending on the condition of thepatient's tibia 720. If the surgeon determines a prosthetic sleeve isnecessary, the procedure 800 advances to procedure block 806 in FIG.21B. If a prosthetic sleeve is unnecessary, the procedure 800 advancesto procedure block 808.

In procedure block 808, the surgeon selects a surgical reamer 18 and astem trial 20. As described above, multiple surgical reamers 18 and/orstem trials 20 may be provided to accommodate prosthetic components ofdifferent sizes. When the surgeon has selected a reamer 18 and the stemtrial 20, the surgeon may assemble the instruments to form anintramedullary orthopaedic surgical instrument 16. To do so, the surgeonaligns the upper end 272 of the stem trial 20 with the aperture 248defined in the tip 244 of the reamer 18. The surgeon may advance theupper end 272 of the trial 20 into contact with the inner wall 250 ofthe reamer 18 to engage the external threads 274 formed on the trial 20with the internal threads of the reamer 18. The surgeon may thread thetrial 20 into the reamer 18 to secure the instruments together.

After the intramedullary orthopaedic surgical instrument 16 isassembled, the procedure 800 advances to procedure block 810. In block810, the surgeon advances the intramedullary orthopaedic surgicalinstrument 16 into the medullary canal 254, as shown in FIG. 23. To doso, the surgeon may secure the shank 242 of the reamer 18 to a powertool and engage the cutting flutes 252 of the reamer 18 with thepatient's tibia 720. The surgeon may then operate the power tool todrill or ream the patient's tibia 720 with the reamer 18 and insert thereamer 18 and the stem trial 20 to the required depth.

When the intramedullary orthopaedic surgical instrument 16 is properlypositioned in proximal end 726 of the patient's tibia 720, the surgeonmay secure the attachment device 12 to the shank 242 of the reamer 18 inprocedure block 812. To do so, the surgeon aligns the passageway 64 ofthe attachment base 30 with the upper end 258 of the shank 242. Thesurgeon may then press on the handles 82 of the levers 72 in thedirection indicated by arrows 730 in FIG. 24 to rotate the levers 72 andremove the catches 78 from the passageway 64. The surgeon may advancethe attachment base 30 downward over the shank 242 until the lower end42 of the base 30 engages the platform 256 of the reamer 18. The surgeonmay release the handles 82, thereby permitting the springs 100 to rotatethe levers 72 into the engaged position. In that position, the catches78 are received in the recess 262 formed in the shank 242, therebysecuring the attachment device 12 to the reamer 18.

Returning to FIG. 21A, the procedure 800 advances to procedure block 814in which the cutting block 14 is moved into position for the resectionof the proximal end 726 of the patient's tibia 720. To do so, thesurgeon may secure the cutting block 14 to the mounting frame 32, asshown in FIG. 24. In the illustrative embodiment, the surgeon may graspthe control knob 158 and operate the control knob 158 to move the plug150 to the disengaged position. The surgeon may then align the slot 210of the cutting block 14 with the plug 150 and the apertures 172 with thealignment pins 170 of the mounting frame 32. The cutting block 14 may beadvanced over the plug 150 and the alignment pins 170, and the surgeonmay operate the control knob 158 to rotate the plug 150 such that theflanges 152 of the plug 150 are received in the channel 154 defined inthe cutting block 14, thereby securing the cutting block 14 to themounting frame 32. The surgeon may position the mounting frame 32 on therails 36, 38 of the attachment base 30 and slide the mounting frame 32(and hence cutting block 14) into position relative to the tibia 720.

After the cutting block 14 is positioned, the surgeon may perform theresection in procedure block 816. To do so, the surgeon may use thecutting guides 220 defined in the cutting block 14, as shown in FIG. 24.For example, the surgeon may select the cutting guide 220 of the cuttingblock 14 corresponding to a desired amount of bone to be removed. Thesurgeon may perform the resection by inserting a bone saw blade 732 intothe selected cutting guide 220 of the cutting block 14. The resectionremoves a proximal portion of the patient's tibia 720 to create asubstantially planar proximal surface 734.

The surgeon may also utilize fastener guides 226 to attach one or morefixation pins 230 to the patient's tibia 720. After securing the cuttingblock 14 to the tibia 720 with fixation pins 230, the surgeon may removethe attachment device 12, the reamer 18, and the stem trial 20 from thetibia 720 prior to performing the resection.

After performing the resection, the surgeon may assemble a tibial traytrial 432 in procedure block 818. To do so, the surgeon may select abase trial 436 and a modular stem 630 and secure those instrumentstogether with the stem trial 20, as shown in FIG. 25. To secure themodular stem 630 to the base trial 436, the base trial 436 is alignedwith the modular stem 630 and the lower end 518 of the fastener 512 isadvanced into the bore 668. The external threads 522 formed on thefastener 512 are advanced into contact with the internal threads 676 ofthe modular stem 630. By rotating the fastener 512 about thelongitudinal axis 530, the internal threads 676 are engaged withexternal threads 522, thereby securing the modular stem 630 to the basetrial 436. When the base trial 436 is seated on the top surface 656 ofthe modular stem 630, the outer sleeve 520 of the fastener 512 ispositioned in the bore 668 of the modular stem 630.

To secure the stem trial 20 to the modular stem 630, the surgeon mayalign the upper end 272 of the stem trial 20 with the aperture 638defined in the tip 634 of the modular stem 630. The surgeon may advancethe upper end 272 of the trial 20 into contact with the inner wall 640of the modular stem 630 to engage the external threads 274 formed on thetrial 20 with the internal threads of the modular stem 630. The surgeonmay thread the trial 20 into the modular stem 630 to secure theinstruments together.

In the procedure block 820, the tibial tray trial 432 is inserted intothe medullary canal 254 of the patient's tibia 720. To do so, thesurgeon may align the stem trial 20 and the modular stem 630 with theopening 724 of the canal 254, as shown in FIG. 25. The surgeon may thenadvance the tibial tray trial 432 downward such that the stem trial 20and the modular stem 630 are positioned in the medullary canal 254 andthe tibial base trial 436 is engaged with the surgically-preparedproximal surface 734 of the tibia 720.

After the tibial tray trial 432 is positioned, the surgeon may perform atrial reduction in procedure block 822. To do so, the surgeon mayposition the check insert 570 in the plate opening 450 defined in thetibial base trial 436 as shown in FIG. 26. Once the selected checkinsert 570 is properly seated, the surgeon may select a trial shim 682and a tibial bearing surface trial 680.

For example, if the surgeon desires a mobile bearing trial, the surgeonmay position the selected trial shim 682 on the tibial tray trial 432.As shown in FIG. 27, the surgeon aligns the aperture 708 of the shim 682with the button head 514 of the fastener 512 and the lug 544 of theinsert 570. The surgeon then places the shim 682 over the button head514 and the lug 544 to seat the shim 682 on the base trial 436. Whenproperly seated, the lug 544 is received in the slot 716 of the shim682.

The surgeon may select a mobile bearing surface trial 700 and attach thetrial 700 to the shim 682. To do so, the surgeon aligns thethrough-holes 710 of the shim 682 with the pegs of the bearing surfacetrial 700. The surgeon then advances the pegs into the respectivethrough-holes 710 such that the lower surface 704 of the mobile bearingsurface trial 700 is placed in contact with the shim 682 to assemble themobile bearing trial.

The surgeon may extend the knee and note the anteroposterior stability,medial-lateral stability, and overall alignment in the A/P and M/Lplanes. The surgeon may also able to assess the bearing rotation andpatellofemoral tracking because the mobile bearing surface trial 700 isrotatable relative to the base trial 436. The surgeon may continue totry various combinations of shims 682 and bearing surface trials 700 toascertain which implant size and configuration (e.g., the thickness ofthe implant, the mobility of the implant, etc.) will have the beststability in flexion and extension while permitting the desiredkinematics.

If the surgeon desires a fixed bearing trial, the surgeon may select afixed bearing surface trial 684 and secure the trial 684 to the shim682. The surgeon may then position the selected trial shim 682 (andbearing surface trial 684) on the tibial tray trial 432. The surgeon mayalign the aperture 708 of the shim 682 with the button head 514 of thefastener 512 and the lug 544 of the insert 570. The surgeon may thenplace the shim 682 over the button head 514 and the lug 544 to seat theshim 682 on the base trial 436. When properly seated in the fixedbearing orientation, the lug 544 is received in the slot 714 of the shim682 such that the shim 682 (and hence bearing surface trial 684) is notpermitted to rotate relative to the base trial 436.

When the fixed bearing surface trial 684 is in place, the surgeoncarefully extends the knee of the patient, noting the anteroposteriorstability, medial-lateral stability, and overall alignment in theanterior-posterior (“A/P”) plane and medial-lateral (“M/L”) plane.Rotational alignment of the tibial base trial 436 may be adjusted withthe knee moving through the range of motion, rotating the trial 436,shim 682, and the bearing trial 684. The surgeon sets the rotation ofthe base trial 436 by assessing multiple factors including femoralposition and tibial plateau coverage. The surgeon may continue to tryvarious combinations of shims 682 and bearing surface trials 684 toascertain which implant size and configuration (e.g., the thickness ofthe implant, the mobility of the implant, etc.) will have the beststability in flexion and extension while permitting the desiredkinematics. After completing trial reduction, the surgeon may fix thetibial tray trial 432 into position by inserting one or more fixationpins into the fastener guides 498.

Returning to FIG. 21A, the procedure 800 may advance to procedure block824 in which the surgeon continues the tibial preparation by impactingthe keel punch insert 572 into the proximal end 726 of the tibia 720. Todo so, the surgeon removes the check insert 570 from the base trial 436,as shown in FIG. 28. The surgeon may then secure the punch insert 572 tothe attachment tool 566 by aligning the pegs 598, 604 of the attachmenttool 566 with the bores 558, 560, respectively, of the punch insert 572and advancing the pegs 598, 604 into the bores 558, 560.

The surgeon may secure the attachment tool 566 to an impaction handle740 by engaging a catch (not shown) of the impaction handle 740 with theflange 616 formed on the attachment tool 566. After securing the handle740 to the tool 566 and the punch insert 572, the surgeon may align thelower arms 574, 576 of the punch insert 572 with the passageways 460,462 defined in the base trial 436. The surgeon may then advance thepunch insert 572 downward such that the lower arms 574, 576 pass throughthe passageways 460, 462 and into the proximal end 726 of the tibia 720.

The surgeon may then drive the punch insert 572 into the tibia 720 bystriking the handle 740 with mallet, sledge, or other impaction tool. Asthe punch insert 572 is driven into the bone, the cutting teeth 580 ofthe punch insert 572 engage the patient's tibia 720 to form additionalslots (not shown) in the tibia 720. When the punch insert 572 is seatedon the tibial base trial 436, the lower arms 574, 576 extend outwardlyfrom the slot 652 defined in the modular stem 630.

After the keel punch insert 572 has been driven into the tibia 720, theprocedure 800 may advance to the procedure block 824. In block 824, thesurgeon may remove the tibial tray trial 432 and the punch insert 572from the proximal end 726 of the patient's tibia 720. To do so, thesurgeon may attach a removal tool 750 to the impaction handle 740, asshown in FIG. 29. The removal tool 750 has a slot 752 defined thereinsized to receive the button head 514 of the fastener 512 and a pair ofengagement arms 754 configured to be positioned between the button head514 and the plate 442 of the tibial base trial 436. When the removaltool 750 is positioned as shown in FIG. 29, the surgeon may pull in thedirection indicated by arrow 756 to disengage the tibial tray trial 432and the punch insert 572 from the tibia 720 such that the surgeon mayproceed with the implantation of the prosthetic components.

Returning to block 804, if the surgeon determines a prosthetic sleeve isnecessary, the procedure 800 advances to procedure block 806 in FIG.21B. In procedure block 806, the surgeon selects a stem trial 20 and abroach assembly 22. As described above, multiple stem trials 20 and/orbroach assemblies 22 may be provided to accommodate prostheticcomponents of different sizes. When the surgeon has selected a stemtrial 20 and the broach assembly 22, the surgeon may assemble theinstruments to form an intramedullary orthopaedic surgical instrument16. To do so, the surgeon aligns the upper end 272 of the stem trial 20with the aperture 302 defined in the tip 286 of the broach 280. Thesurgeon may advance the upper end 272 of the trial 20 into contact withthe inner wall 304 of the broach 280 to engage the external threads 274formed on the trial 20 with the internal threads of the reamer 18. Thesurgeon may thread the trial 20 into the broach 280 to secure theinstruments together.

After the intramedullary orthopaedic surgical instrument 16 is assembledin block 806, the procedure 800 advances to procedure block 828. Inblock 828, the surgeon may advance the stem trial 20 and the broachassembly 22 into the medullary canal 254, as shown in FIG. 30. To do so,the surgeon may secure the broach assembly 22 with the impaction handle740 by engaging the catch of the impaction handle 740 with the flange354 of the broach 280. After securing the handle 740 to the broachassembly 22, the surgeon may align the stem trial 20 with the medullarycanal 254. The surgeon may then drive the stem trial 20 and the broachassembly 22 into the tibia 720 by striking the handle 740 with mallet,sledge, or other impaction tool. As the broach assembly 22 is driveninto the bone, the cutting teeth 290 of the broach 280 and the cuttingteeth 388 of the broach insert 282 engage the patient's tibia 720 toshape the medullary canal 254 to receive the prosthetic sleeve.

The procedure 800 may then advance to procedure block 830 in which thesurgeon removes the broach insert 282 from the broach 280. To do so, thesurgeon may reorient the impaction handle 740 to engage the catch withthe flange 380 of the broach insert 282. As shown from the posteriorperspective view in FIG. 31, the surgeon may pull the handle 740 in thedirection indicated by arrow 758 to disengage the cutting teeth 388 ofthe broach insert 282 and detach the broach insert 282 from the broach280.

After the broach insert 282 is removed in block 832, the surgeon maysecure the attachment device 12 to the broach 280 in procedure block832. To do so, the surgeon may attach the adaptor 400 to the broach 280,as shown the posterior perspective view in FIG. 32. The surgeon mayalign the post 416 of the adaptor 400 with the bore 338 defined in theplatform 328 of the broach 280 before advancing the adaptor 400 downwardsuch that the plug 404 is positioned in the slot 316 of the broach 280and the post 416 is received in the bore 338. The biasing element 418engages the inner wall 310 of the broach 280 to secure the adaptor 400to the broach 280. When the adaptor 400 is properly positioned on thebroach 280, the base 402 of the adaptor 400 is seated on the top surface306, and the shaft 422 extends upwardly from the tibia 720.

The surgeon may secure the attachment device 12 to the adaptor 400 byaligning the passageway 64 of the attachment base 30 with the shaft 422.The surgeon may then press on the handles 82 of the levers 72 in thedirection indicated by arrows 730 in FIG. 33 to rotate the levers 72 andremove the catches 78 from the passageway 64. The surgeon may advancethe attachment base 30 downward over the shaft 422 until the lower end42 of the base 30 engages the plug 404 of the adaptor 400 and the topsurface 306 of the broach 280. The surgeon may release the handles 82,thereby permitting the springs 100 to rotate the levers 72 into theengaged position. In that position, the catches 78 are received in the424 formed in the shaft 422, thereby securing the attachment device 12to the adaptor 400 (and hence the broach 280).

Returning to FIG. 21B, the procedure may advance to block 814 in whichthe cutting block 14 is moved into position for the resection of theproximal end 726 of the patient's tibia 720. As described above, thesurgeon may secure the cutting block 14 to the mounting frame 32 andposition the mounting frame 32 on the rails 36, 38 of the attachmentbase 30. The surgeon may then move the mounting frame 32 (and hencecutting block 14) into position relative to the tibia 720.

The procedure 800 may then advance to procedure block 834 in which thesurgeon performs the resection of the tibia 720. Similar to procedureblock 816 described above, the surgeon may use the cutting guides 220defined in the cutting block 14, as shown in FIG. 24. For example, thesurgeon may select the cutting guide 220 of the cutting block 14corresponding to a desired amount of bone to be removed. The surgeon mayperform the resection by inserting a bone saw blade 732 into theselected cutting guide 220 of the cutting block 14. The resectionremoves a proximal portion of the patient's tibia 720 to create asubstantially planar proximal surface 734.

After performing the resection, the surgeon may assemble a tibial traytrial 432 in procedure block 836. To do so, the surgeon may secure thebase trial 436 to the broach 280 via the fastener 512. The base trial436 may aligned with the broach 280 and the lower end 518 of thefastener 512 is advanced into the bore 338. The external threads 522formed on the fastener 512 are advanced into contact with the internalthreads 346 of the broach 280. By rotating the fastener 512 about thelongitudinal axis 530 using the button head 514, the internal threads346 are engaged with external threads 522, thereby securing the broach280 to the base trial 436. When the base trial 436 is seated on the topsurface 306 of the broach 280, the outer sleeve 520 of the fastener 512is positioned in the bore 338 of the broach 280, and the tibial basetrial 436 is engaged with the surgically-prepared proximal surface 734of the tibia 720.

After the tibial tray trial 432 is positioned, the surgeon may perform atrial reduction in procedure block 822. As described above, the surgeonmay position the check insert 570 in the plate opening 450 of the tibialbase trial 436 before selecting a trial shim 682 and a tibial bearingsurface trial 680. Thereafter, the surgeon may adjust the patient's legto evaluate performance and ascertain which implant size andconfiguration (e.g., the thickness of the implant, the mobility of theimplant, etc.) will have the best stability in flexion and extensionwhile permitting the desired kinematics. Because the base trial 436 ispermitted to rotate relative to the broach 280, the surgeon is able toestablish the rotational position of the tibial tray prostheticcomponent based on the femoral position and best fit coverage of thetibial plateau.

As shown in FIG. 21B, the procedure 800 may advance to procedure block838 in which the surgeon continues the tibial preparation by impactingthe keel punch insert 572 into the proximal end 726 of the tibia 720.Similar to procedure block 824 described above, the surgeon removes thecheck insert 570 from the base trial 436, as shown in FIG. 28. Thesurgeon may then secure the punch insert 572 to the attachment tool 566by aligning the pegs 598, 604 of the attachment tool 566 with the bores558, 560, respectively, of the punch insert 572 and advancing the pegs598, 604 into the bores 558, 560.

The surgeon may secure the attachment tool 566 to an impaction handle740 by engaging a catch (not shown) of the impaction handle 740 with theflange 616 formed on the attachment tool 566. After securing the handle740 to the tool 566 and the punch insert 572, the surgeon may align thelower arms 574, 576 of the punch insert 572 with the passageways 460,462 defined in the base trial 436. The surgeon may then advance thepunch insert 572 downward such that the lower arms 574, 576 pass throughthe passageways 460, 462 and into the proximal end 726 of the tibia 720.

The surgeon may then drive the punch insert 572 into the tibia 720 bystriking the handle 740 with mallet, sledge, or other impaction tool. Asthe punch insert 572 is driven into the bone, the cutting teeth 580 ofthe punch insert 572 engage the patient's tibia 720 to form additionalslots (not shown) in the tibia 720. When the punch insert 572 is seatedon the tibial base trial 436, the lower arms 574, 576 extend outwardlyfrom the slot 316 defined in the broach 280.

After the keel punch insert 572 has been driven into the tibia 720, theprocedure 800 may advance to the procedure block 824. In block 824, thesurgeon may remove the tibial tray trial 432 and the punch insert 572from the proximal end 726 of the patient's tibia 720. To do so, thesurgeon may attach a removal tool 750 to the impaction handle 740 anduse the removal tool to the tibial base trial 436, the punch insert 572,broach 280, and stem trial 20 from the tibia 720 such that the surgeonmay proceed with the implantation of the prosthetic components.

While the disclosure has been illustrated and described in detail in thedrawings and foregoing description, such an illustration and descriptionis to be considered as exemplary and not restrictive in character, itbeing understood that only illustrative embodiments have been shown anddescribed and that all changes and modifications that come within thespirit of the disclosure are desired to be protected.

There are a plurality of advantages of the present disclosure arisingfrom the various features of the method, apparatus, and system describedherein. It will be noted that alternative embodiments of the method,apparatus, and system of the present disclosure may not include all ofthe features described yet still benefit from at least some of theadvantages of such features. Those of ordinary skill in the art mayreadily devise their own implementations of the method, apparatus, andsystem that incorporate one or more of the features of the presentinvention and fall within the spirit and scope of the present disclosureas defined by the appended claims.

1. An orthopaedic surgical instrument assembly comprising: a tibialbearing trial including an articulation surface and a bottom surfaceopposite the articulation surface, a tibial base trial adapted to bepositioned on a surgically-prepared proximal end of a patient's tibia,the tibial base trial includes an upper surface engaged with the bottomsurface of the tibial bearing trial, an intramedullary orthopaedicsurgical instrument engaged with a lower surface of the tibial basetrial, and a fastener configured to pivot relative to the tibial basetrial, the fastener including (i) a button head positioned in anaperture defined in the tibial bearing trial, and (ii) a threaded shaftengaged with the intramedullary orthopaedic surgical instrument toremovably couple the intramedullary orthopaedic surgical instrument tothe tibial base trial.
 2. The orthopaedic surgical instrument assemblyof claim 1, wherein the intramedullary orthopaedic surgical instrumentincludes a broach engaged with the threaded shaft, the broach having (i)a tapered outer surface, and (ii) a plurality of cutting teeth formed onthe tapered outer surface.
 3. The orthopaedic surgical instrumentassembly of claim 2, further comprising a second intramedullaryorthopaedic surgical instrument configured to be engaged with thethreaded shaft of the fastener in place of the broach.
 4. Theorthopaedic surgical instrument assembly of claim 3, wherein the secondintramedullary orthopaedic surgical instrument includes a stem trial. 5.The orthopaedic surgical instrument assembly of claim 1, wherein: thetibial base trial includes (i) a plate having an opening defined in theupper surface thereof, and (ii) a platform positioned in the opening ofthe plate, and the fastener extends through a bore defined in theplatform.
 6. The orthopaedic surgical instrument assembly of claim 5,further comprising a base insert positioned in the opening defined inthe plate of the tibial base trial, the base insert including a lugpositioned in the aperture defined in the tibial bearing trial.
 7. Theorthopaedic surgical instrument assembly of claim 6, wherein: the baseinsert further includes (i) a frame having a circular opening definedtherein, and (ii) a pair of prongs extending outwardly from the frame,and the platform of the tibial base trial is positioned in the circularopening.
 8. The orthopaedic surgical instrument assembly of claim 7,wherein the base insert further includes: a first lower arm attached toa first prong of the pair of prongs, the first lower arm extendingthrough an opening defined in the lower surface of the tibial base trialand having (i) a tapered outer surface, and (ii) a plurality of cuttingteeth formed on the tapered outer surface, and a second lower armattached to a second prong of the pair of prongs, the second lower armextending through an opening defined in the lower surface of the tibialbase trial and having (i) a tapered outer surface, and (ii) a pluralityof cutting teeth formed on the tapered outer surface.
 9. The orthopaedicsurgical instrument assembly of claim 8, wherein the intramedullaryorthopaedic surgical instrument includes a slot, and the first lower armand the second lower arm are received in and extend outwardly from theslot.
 10. The orthopaedic surgical instrument assembly of claim 1,wherein the tibial bearing trial includes: a tibial bearing surfacetrial including the articulation surface, and a shim secured to thetibial bearing surface trial, the shim including the bottom surface. 11.An orthopaedic surgical instrument assembly comprising: a tibial basetrial adapted to be positioned on a surgically-prepared proximal end ofa patient's tibia, a fastener configured to pivot relative to the tibialbase trial, the fastener including (i) a button head, and (ii) athreaded shaft extending through the tibial base trial, anintramedullary orthopaedic surgical instrument secured to the fastener,and a base insert positioned in an opening defined in the tibial basetrial.
 12. The orthopaedic surgical instrument assembly of claim 11,further comprising an attachment tool configured to engage the baseinsert to attach and detach the base insert from the tibial base trial.13. The orthopaedic surgical instrument assembly of claim 12, wherein:the base insert has a pair of openings defined therein, and theattachment tool includes a pair of pegs configured to be received in theopenings of the base insert, each peg including a spring configured toengage the base insert to secure the attachment tool to the base insert.14. The orthopaedic surgical instrument assembly of claim 11, whereinthe base insert includes a keel punch, the keel punch having: a firstarm extending through a lower surface of the tibial base trial, thefirst arm having (i) a tapered outer surface, and (ii) a plurality ofcutting teeth formed on the tapered outer surface, and a second armextending through the lower surface of the tibial base trial, the secondarm having (i) a tapered outer surface, and (ii) a plurality of cuttingteeth formed on the tapered outer surface.
 15. The orthopaedic surgicalinstrument assembly of claim 14, wherein the intramedullary orthopaedicsurgical instrument includes a slot, and portions of the first arm andthe second arm are received in and extend outwardly from the slot. 16.The orthopaedic surgical instrument assembly of claim 15, wherein theintramedullary orthopaedic surgical instrument includes a broach engagedwith the threaded shaft, the broach having (i) a tapered outer surface,and (ii) a plurality of cutting teeth formed on the tapered outersurface.
 17. The orthopaedic surgical instrument assembly of claim 11,wherein the base insert includes (i) a frame, (ii) a pair of prongsextending outwardly from the frame, and (iii) a lug extending upwardlyfrom the frame adjacent to the button head of the fastener.
 18. Theorthopaedic surgical instrument assembly of claim 17, furthercomprising: a tibial bearing trial coupled to the tibial base trial, thetibial bearing trial including (i) a tibial bearing surface trial havingan articulation surface, and (ii) a shim having an aperture definedtherein, wherein the lug of the base insert and the button head of thefastener are positioned in the aperture.
 19. An orthopaedic surgicalinstrument assembly comprising: a tibial base trial adapted to bepositioned on a surgically-prepared proximal end of a patient's tibia,the tibial base trial including (i) a plate having an opening defined inan upper surface thereof, and (ii) a platform positioned in the openingof the plate, a fastener configured to pivot relative to the tibial basetrial, the fastener including (i) a button head positioned above theupper surface, and (ii) a threaded shaft extending through a boredefined in the platform of the tibial base trial, a first base insertpositioned in the opening defined in the tibial base trial including (i)a frame positioned over the platform of the tibial base trial, and (ii)a pair of prongs extending outwardly from the frame, and a second baseinsert configured to be positioned in the opening in place of the firstbase insert, wherein the second base insert includes: a first armextending through a lower surface of the tibial base trial, the firstarm having (i) a tapered outer surface, and (ii) a plurality of cuttingteeth formed on the tapered outer surface, and a second arm extendingthrough the lower surface of the tibial base trial, the second armhaving (i) a tapered outer surface, and (ii) a plurality of cuttingteeth formed on the tapered outer surface.
 20. The orthopaedic surgicalinstrument assembly of claim 19, further comprising a plurality ofintramedullary orthopaedic surgical instruments, each intramedullaryorthopaedic surgical instrument being configured to engage the fastenerto secure the intramedullary orthopaedic surgical instrument to thetibial base trial.